2 Stroke vs 4 stroke

[Craig_B]

I have an 1963 Pengor Penguin that was originally powered by a 10hp 2 stroke motorcycle engine.
The motor could be started in the opposite direction to give you reverse gears.
I am pondering the idea of replacing it with something more modern if I cannot repair the original.

I have seen some small 4 stroke motors (chinese) on ebay that also have reverse. They claim 7.5kw of power which converts to 10hp.

Would they be the equivalent of 10hp 2 stroke?

Thanks

[dirtdobber]

Hi Craig, the answer is simple yet complex. 7.5 kw of power does translate into 10 hp. However, you need to also consider torque. A high revving engine can have a respectable level of horse power but produce fairly low torque, while a low revving engine (a big diesel engine for example) will produce limited horsepower but high torque. I think the engine type will depend on your desired riding style. Folks on this site prefer the four stroke engines for trail riding because of the slower speed / higher torque combination. The racers like the 2 strokes for their high rpm hp and speed.

[Craig_B]

This wont really be either a trail machine or racer.
Just to put around and play a little in a museum piece.

[ARGOJIM]

I would recommend a 4 stroke for general putting with less tuning, as far as working easy it would mainly depend on the high rpm of the Villiers to start with as if it were only 4,000 rpm, the torque of the 4 stroke would probably out propel it and near top speed. Also to be considered is the drive system, does that use a cvt clutch setup or is it a friction type drive?
Mostly are you looking for originality? If so I would check vintage sled sites for a villiers specialist, maybe up there somewhere on a sled forum or facebook page.

[Craig_B]

I would recommend a 4 stroke for general putting with less tuning, as far as working easy it would mainly depend on the high rpm of the Villiers to start with as if it were only 4,000 rpm, the torque of the 4 stroke would probably out propel it and near top speed. Also to be considered is the drive system, does that use a cvt clutch setup or is it a friction type drive?
Mostly are you looking for originality? If so I would check vintage sled sites for a villiers specialist, maybe up there somewhere on a sled forum or facebook page.

It has a motorcycle engine engine (internal 4 speed gearbox) connected with a chain to a jackshaft then to the rear axle.
I cannot find Anyone who has any knowledge of Villiers engines and specifically the Dynastart these engines use.
I have been looking for years.

[techfx]

This might be a useful thread:

http://www.6x6world.com/forums/engin...le-engine.html

[ARGOJIM]

I'm thinking the easiest route may be to find a earlier gas golf cart, some of those ran both ways with the starter generator reversing them.

[jerseybigfoot]

The small Chinese kart engines with reverse should work fine. It may be more of an issue selecting a proper gear ratio and fitting the required sprockets. Adding a jackshaft can help sort out the ratios and engine /drive location. Your only issue would be cooling.

[Kevin Percy]

A follow up for anyone for anyone interested. The Villiers motor has been torn down, various parts replaced and the Dynastart has been cleaned up and the coils of the stator re-wrapped. The process was documented and uploaded to youtube in a 15 part series titled "Penguin Engine And Transmission Teardown" and a test run of the engine in a different Penguin can be seen at about the 50 minute mark of part 15, a preview is attached.

https://youtu.be/saeM0ORsJMY